Straw-burning boiler-furnace



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STRAW BURNING BOILER FURNAGE.

Patented July 19; 1881.

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A. A. CULVER. STRAW BURNING BOILBRI'URNAGE.

No. 244,436. Patented July 19,1881:

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No. 244,436. Patented July 19,1881.

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STRAW BURNING BOILER FURNACE. N0; 244",436. v Patented July'19, 1881.

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ALBERT A. OULVER, OF VALLEY CITY, DAKOTA TERRITORY, ASSIGNOR OF ONE-HALF TO STEPHEN FREEMAN, OF RAGINE, WISCONSIN.

STRAW-BURNING BOILER-FURNACE.

S PEGIFIQATION formingpart of Letters Patent No. 244,436, dated July 19, 1881.

. Application filed January 31, 1881. (No model.) I

To all whom it may concern:

Be it known that I, ALBERT A. CULVER, of Valley City, in the county of Barnes and Territory of Dakota, have invented certain new and useful Improvements in Straw-Burning Boiler-Furnaces and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, and to the letters of reference marked thereon, which form a part of this specification.

Myinvention relates to straw-burnin g steamboiler furnaces; and it consists in the combination, with a traveling endless grate moving away from the point of feed, of a pair of feedingrolls which deliver the straw upon the grate.

It further consists in the combination, with a traveling grate, of an air inlet and outlet, ar-

ranged to give passage to the air through the furnace or fire-box in opposition to the direction of movement of the grate.

It finally consists in other features of construction and operation, which, together with the foregoing, will be hereinafter more fully set forth, and pointed outin the claims.

In the drawings, Figure 1 is a central vertical longitudinal section of the boiler and furnace. Fig.2 is a horizontal section above the grate through a: as of Fig. 1. Fig.3 is an elevation showing the rear end. Fig. 4is a fragmentary side elevation. Fig. 5 is a transverse vertical section, looking toward 0 and Figs. 6 and 7 are detail views.

Ais the boiler; B, the smoke-flue;tand U the front fire-space at the head of the boiler. B is properly the front of the machine, and G is the rear. It is the fire-box, extending, as here shown, from end to end of a the boiler, which is arched over the same, asindicated in Fig. 5.

The grate D is constructed of transverse bars d, having laterally-projecting lugs 11 at their ends, arranged to overlap one another, as shown in Figs. 2 and 6, and connected by bolts passed through the lugs to form a broad endless open chain. This endless chain is mounted as a sprocket-chain on the pulleys E E, carried, respectively, by the transverse shafts E E located at the front and rear of 0 the fire-box B.

F and F are transverse feed-drums, one above the other, geared together by the long meshing teeth 0 and c. The upper drum, F, is adapted to rise and fall by having its bearing-boxes f arranged to slide in the slots t in the supporting-plates G, which project from the end of the boiler, and said drum is depressed by means of the springs s. It may be depressed by its own weight, or by weighted levers, or in any suitable manner.

In the plate 0, and opposite the meeting line of the drums F and F, is an opening, 0 which is also preferably in line with or a little above the upper surface of the grate D. The shaft E and the lower drum-shaft, F are provided, respectively, at one or both ends, with sprocket-wheels E and F connected by a sprocket-chain, V. The same drum-shaft F is also provided with a driving-pulley, Q, connected with the engine by a belt, so as to rotate the feed-drums inward at their meeting line and the upper surface of the grate forward in the direction of the arrow to.

S represents straw being fed into the furnace and upon the grate by and between the feed-drums F and F.

T is a corrugated plate projected from the foot-plate 0 at a point above the opening 0 downwardly and forward over the grate D, to prevent combustion of the straw until it is well advanced into the fire-box by the traveling grate D.

The feed-drums F and F set close to the foot-plate G, to prevent, as much as possible, the admission of air about them. At the opposite or front end a draft register or opening, H, is located beneath the grate D. The air passes upward through the opening 0 of the grate, and upward through the straw, and is drawn backward in opposition to the course of the straw. The tendency of the draft-is, therefore, to loosen up or separate the straw at the burning-surface of the mass, and con sequently to make combustion more rapid and complete. The space L beneath the front end of the grate D is extended far enough backward to give ample passage to the air admitted at H.

I is a plate, of the full width of the grate D, hinged at its upper edge to the head-plate B, and provided on its lower edge with a roller, I, which rides on the grate.

M is a removable ash-pan, arranged beneath the forward end of the grate D to catch the ashes from the same as it is carried over the drum E. Beneath the grate D at this point is arranged a transverse rotary-brush, m, in contact with the grate, and rotated preferably in opposition to the direction of the grate-sun face by the cross-belt a, connecting pulleys e and m, to detach the ashes that may adhere to the grate and direct their fall into the receptacle M.

P is a transverse prismatic roller, arranged beneath the grate, preferably one ateach edge thereof, on a connecting-shaft, and rotated by the grate through the medium of projections 12, which enter the spaces 0 between the bars d. The object of this device is to shake the grate in its passage, and thereby loosen the straw thereon, to further promote its rapid combustion. Another effect of this movement of the grate will be to shake down the ashes that would otherwise lodge across the opening oandtosome extentobstructthem. Theashes thus dislodged will be swept backward by the under course of grate-bars d, and a suitable opening, 0, is provided for their discharge into an ash-pan, M.

Provision is made for burning wood in the furnace described by the preferably removable grate K, consisting of a number of bars located near the front end of the fire-box. To use this grate it will be necessary to remove the grate D, which will be done by removing a pair of the marginal bolts by which the individual bars (I are connected.

J is a suitable opening and door in the front head-plate B, through which to feed the wood or other fuel to the grate K. I have shown the wood-grate as beingin two sections,K and K, but the bars K may, if preferred, extend forward to the plate B. When this grate is used the airis forced upward through the same by means of the plate N, which may be hinged at n, as shown, or wholly removable. This plate sets up from the bottom of the furnace against the cross-bar K and cuts off passage for the air otherwise than through the grate K. The space L in the use of the grate K is the ash-pit.

It is, of course, understood that the class of boilers and furnaces to which my invention is applied are usually mounted, and that the engine forms a part of the mounted structure.

I have neglected to show the wheels by which the apparatus is made portable,and the engine also, because these parts may be of the ordinary or any preferred construction and arrangement.

If desired,r0llers may be stationed beneath the lower returning face of the grate D to re lieve its weight and lessen or prevent friction.

The advantages of a traveling grate as described will be obvious to those accustomed to the use of straw-burning furnaces. The volume of ashes produced from straw is relatively much greater than in the use of more compact fuel, and its accumulation is a source of constant trouble, as well as a hinderance to combustion, in furnaces heretofore constructed for burning this material. By the devices herein shown the fuel may be loosely exposed to the flame, thereby insuring rapid combustion, and as fast as it is burned theashes produced are removed, so that the grate beneath the burning material is always open and free. Not being continuously exposed to heat, the bars d of the grate D may be comparatively light.

I am aware that feeding-rolls have been heretofore employed in connection with stationary grates, and that traveling grates for coal-burning furnaces are not new. I do not, therefore, broadly claim feeding-rollers or a traveling grate by themselves separate1y,but only when combined in a straw-burnin g furnace,wherein the obstruction of the feed-rolls by the bunching of the straw within the fire-box incident to the use of a stationary grate is thereby avoided, and wherein, on the other hand, the straw is evenly distributed upon the traveling grate by the correspondingly-movin g surfaces of the feed-rolls, arranged to travel in the same direction and nearly in the same plane with the receiving-surface of the grate.

I claim as my invention 1. In combination with a traveling grate of a steam-boiler fire-box, the inlet and outlet airpassages arranged to give direction to the air in opposition to that in which the grate is moving, substantially as described.

2. The combination,iu astraw-burnin g boiler-furnace, of the feed-rollers F and F, arranged at the furnace-mouth, and the traveling grate D, the receiving-surface of which has motion in the same direction as that of the feeding-surfaces of the rollers, substantially as described.

3. In combination with the feeding rollers and the grate, together arranged to carry the straw in the same direction and in opposition to the direction of draft through the fire-box, the plate T, arranged above the feed-aperture and extending over the grate, substantially as described, and for the purposes set forth.

4. In combination with an endless grate emerging from the head of the fire-box, the part I, adapted to rise and fall, and provided with the marginal roller I, substantially as described.

5. In combination with the traveling grate, the brush m, arranged to bear upon the lower or returning surface of the grate, substantially as described.

6. In the fire-box having traveling and station ary grates arranged as described, the valve or deflecting-plate N, substantially as and. for In testimony that I claim the foregoing as the purposes set forth. my invention I-affix my signature in presence 7. In combination with the travelglg endless of two witnesses.

grate D, arranged to run.on' its an er surface 5 near the bottom plate of the furnace,the open- ALBERT GULVER ings O in said bottom, at or nearthe rear end Witnesses: of the grate, substantially as and for the pur- M. E. DAYTON, poses set forth. W. (J. ADAMS. 

